A magnet pole rotor having a multiplicity of magnet poles arranged on the exterior cylindrical face of a base ring of the rotor is known from DE 196 01 271 A1. The magnet poles are embedded in a plastic ring, which is an injection molded component. The plastic ring is pressed on to the exterior cylindrical face of the base ring. A cage ring that laps over the plastic ring is provided to protect against any displacement of the plastic ring on the exterior cylindrical face of the base ring.
DE 199 42 029 A1 discloses a permanent magnet rotor for a brushless electric motor in which the permanent magnet rotor has a cylindrical lamellar rotor body. The said cylindrical lamellar rotor body is fixedly connected to the rotor shaft and has segment-form permanent magnets arranged along the circumference of the cylinder. The said segment-form permanent magnets can be pressed and held against the circumference of the cylinder of the rotor body using a means of fixing. The means of fixing is a series of resilient retaining clamps.
GB 2 275 134 A discloses a permanent magnet rotor for an electric motor with a rotor base body having a cylindrical exterior face. Arranged on the exterior face of this rotor base body are a multiplicity of permanent magnets, it being the case that the permanent magnets are spaced apart from one another. A poured jacket of plastic material or resin that covers the exterior face of the permanent magnets and fills the gaps between the permanent magnets is also provided. The poured jacket, which is itself provided with permanent magnet material, serves to fix the permanent magnets to the rotor and to cause the changes in the magnetic flux between magnets that are adjacent in the circumferential direction to be only gradual.
WO 00/74209 A1 discloses a rotor for a brushless motor in which a shrinkable sleeve is provided to fix in place the magnet segments of the rotor. When this rotor is being assembled, the magnet segments are initially placed loosely in a cage. A rotor core can then be inserted axially into the radial interior region of the magnet segments, which are together arranged in the form of a ring. The magnet segments are fixed in place using the aforementioned shrinkable sleeve. The said shrinkable sleeve initially takes the form of a tube that is made from a material that shrinks when exposed to heat and is pushed over the magnet segments in the axial direction. When the required temperature, which advantageously lies in the range between 100° C. and 200° C., is applied to the said tube, the tube contracts to create a shrink-fitted sleeve that fixes the magnet segments to the rotor.